First off, a quick update on my column from two weeks ago, in case you haven’t heard — the Chinese spacecraft Chang’e-4 successfully landed on the far side of the moon and transmitted back its first pictures. We’ll see what that lander and rover can uncover about the depths of the moon on that unexplored side.

The other big space news from this past week was the spacecraft New Horizons’ flyby of Ultima Thule (which translates to “beyond the known world”). Many of you may have looked at the pictures returned of this object, noticed it looked like a blurry snowman, and wondered why so much was being made about it.

So let’s talk about it. Ultima Thule is what is known as a Kuiper Belt object (KBO), an icy body that lives outside of the orbit of Neptune (sometimes also called a trans-Neptunian object). The Kuiper Belt itself is a doughnut-shaped area far outside much of the heat and glow of the sun, and the objects that orbit in it are remnants from the formation of our solar system.

In case you were wondering, yes, Pluto is also considered to be a KBO. In fact, there are a number of other dwarf planets out in the Kuiper Belt as well, and as our telescopes and observations continue to improve, we’re probably going to find a lot more. Current estimates say that there might be hundreds of thousands of KBOs larger than 62 miles across and a trillion or more comets in this area of space. But all those objects would make up only about 10 percent of Earth’s mass if combined together, estimates say.

What else do we know about these objects? Aside from size (they all tend to be much smaller than Earth’s moon), they’re not too different from some of our solar system’s main planets. We’ve uncovered several (including Pluto) that have moons, and one that even has a ring system. We’ve also found that some of the dwarf planets out there possess thin atmospheres, though they disappear when they are at the apogee of their orbit, or the furthest distance from the sun. We don’t know yet what this means for life out there in the cold.

Ultima Thule is a special kind of KBO called a contact binary, which is what gives it that snowman shape. It actually began its life as two different objects that spiraled together in the early days of the solar system and merged around a shared center of mass. We believe that binary KBOs are particularly old and haven’t changed much since the formation of the solar system, which makes them great to study in our search for understanding how the solar system was created.

We don’t have all of the data New Horizons has collected yet, which will continue to be transmitted as the spacecraft zooms on into space. There may yet be a stop at a different KBO on the spacecraft’s agenda if a mission extension is approved by NASA. But for now, we’ll just have to wait and see what scientists uncover sifting through all this new information on Ultima Thule.

LOOKING UP THIS WEEK: Mars is your only evening planet, starting in the southwest at dusk, but will stay up late into the night. Jupiter and Venus are in the southeast an hour before sunrise, with Jupiter the lower of the two for the moment. The moon is currently a waxing crescent and will be first quarter on Sunday.